Mission Type: Flyby, Orbiter
Launch Vehicle: Delta 7925-10 (no. D227)
Launch Site: Cape Canaveral, USA; ESMC / launch complex 17B
NASA Center: Goddard Space Flight Center
Spacecraft Mass: 1,250 kg
Spacecraft Instruments: 1) Hot Plasma and Charged Particles (3DP); 2)Transient Gamma Ray and EUV Spectrometer (TGRS); 3) Magnetic Fields Instrument (MFI); 4) Plasma and Radio Waves (WAVES); 5) Solar Wind Experiment (SWE); 6) Energetic Particle Acceleration, Composition and Transport (EPACT); 7) Solar Wind and Suprathermal Ion Composition Studies (SWICS/STICS) and 8) Gamma Ray Burst Detector (KONUS)
Spacecraft Dimensions: Cylinder, about 2.8 m in diameter by 1.25 m high
Spacecraft Power: Solar
Maximum Data Rate: 11.1 kbps
References:
Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, Monographs in Aerospace History No. 24, by Asif A. Siddiqi

National Space Science Data Center, http://nssdc.gsfc.nasa.gov/

Wind 2010 Senior Review Proposal

Wind is the interplanetary component of the Global Geospace Science Program within the International Solar Terrestrial Physics (ISTP) program, a cooperative satellite project which also includes the Geotail, Polar, SOHO, and Cluster missions. The United States, Japan, Russia, the Czech Republic, and ESA all participate in the ISTP project to study the behavior of the solar-terrestrial system.

The first of two NASA-sponsored Global Geospace Science Program vehicles, the Wind spacecraft carries eight instruments (including one each from France and Russia) to investigate the solar wind's encounters with Earth's magnetosphere and ionosphere in order to determine the origins and three-dimensional characteristics of the solar wind.

Wind initially operated in a unique figure-eight-shaped elliptical orbit around Earth at 28,000 x 1.6 million kilometers, partially maintained by regular "double flybys" of the Moon. The closest of 19 flybys of the Moon between 1 December 1994 and 17 November 1998 was on 27 December 1994, at a range of 11,834 kilometers.

By November 1996, Wind was in a "halo orbit" around Earth-Sun Lagrangian libration point L1, a point 1.5 million kilometers from Earth toward the Sun. At L1, Earth's gravity counterbalances that of the Sun such that an object at that location takes one Earth year to orbit the Sun, despite having a distance from the Sun that normally would require a faster orbit. The object thus remains directly between Earth and the Sun. From there, Wind was able to provide about a one-hour warning of changes in the solar wind to the other ISTP spacecraft.

On 17 November 1998, Wind began to move into a series of "petal" orbits designed to take it out of the ecliptic plane. Wind's trips above and below the ecliptic (up to 60?) allowed the spacecraft to sample regions of interplanetary space and the magnetosphere that had been sampled only rarely. Between 2000 and 2002, Wind moved further and further away from the Sun-Earth line, reaching 350 Earth radii to the side in a distant prograde orbit. Finally, in 2003, it completed an L2 campaign taking the spacecraft more than 250 Earth radii downstream of Earth to investigate solar wind evolution and magnetotail phenomena.

Since 2004, Wind has remained at L1 where it will stay for the foreseeable future. All of its instruments are still functioning as of 2010, except for one of the gamma-ray instruments (TGRS).